HLT 362V Exercise 20

1. Which patient scored the highest on the preoperative CVLT Acquisition? What was his or her T score?

Patient 3 with a T score of 63

2. Which patient scored the lowest on postoperative CVLT Retrieval? What was this patient’s T score?

Patient 4 with a T score of 23

3. Did the patient in Question 2 have more of a memory performance decline than average on the CVLT Retrieval? Provide a rationale for your answer.

According to the case study the average drop in CVLT Retrieval was 9.6. Patient 4 had a drop of 44-23 = 21. This is more than twice the average. Hence patient 4 most definitely experienced a greater memory performance decline than the average.

4. What is the mean (overbar above X ) and standard deviation (SD) for preoperative T score for CVLT Acquisition?

Using excel the mean can be found by the following formula, X = AVERAGE(44,42,63,46,51,48,42,46,50,42,44,42,45,46,44,46,47) = 46.35 and the standard deviation, SD = STDEV(44,42,63,46,51,48,42,46,50,42,44,42,45,46,44,46,47) = 5.06

5. Is the preoperative Retrieval T score for Patient 5 above or below the mean for the norm of the group? Provide a rationale for your answer.

Mean = AVERAGE(51,51,58,44,52,52,44,45,54,41,42,48,60,41,50,44,46) = 48.41 The mean of the preoperative Retreival T score from question 4 is 48.41. Patient 5 had a preoperative T score of 52. Hence patient 5’s T score is above the mean.

6. Assuming that the distribution of the preoperative CVLT Retrieval T scores is normal, the middle 68% of the patients had T scores between what two values?

SD = STDEV(51,51,58,44,52,52,44,45,54,41,42,48,60,41,50,44,46) = 5.73. 68% of the values lie within 1 standard deviation of the mean. Therefore the interval is, (48.41-5.73, 48.41+5.73) = (41.29, 51.41)

7. Assuming that the distribution of scores for the postoperative CVLT Retrieval T scores is normal, the middle 68% of the patients had T scores between what two values?

Mean = AVERAGE(47,51,58,23,40,40,44,36,37,37,34,31,39,24,46,35,46) = 39.29

SD = STDEV(47,51,58,23,40,40,44,36,37,37,34,31,39,24,46,35,46) = 9.0. Therefore the interval is,

(39.29-9.0, 39.29+9.0) = (30.29, 48.29)

8. The researchers state that it appears that the functional integrity of the left temporal lobe, despite evidence of structural abnormality, plays a considerable role when it comes to memory outcomes following left ATL. Can the findings from this study be generalized to a larger population? Provide a rationale for your answer.

No, because according to the article, “the researchers do recognize the limitations of their study and note that the small sample size restricts the generalizations of the study findings” this statement implies that the findings cannot be generalized to the larger population.

9. If a patient had a raw score = 30, what would his/her postoperative CVLT Retrieval T score be?

T score = 10(30)/9.0+(50-10(39.29)/9.0) = 39.68

10. Did patients demonstrate more postoperative memory declines among CVLT Retrieval T scores than CVLT Acquisition T scores? Provide a rationale for your answer.

The average drop in CVLT Retrieval T scores was reported to be 9.6 (a decline of 20% from the baseline), while the average drop in CVLT Acquisition T scores was reported to be 6.9 (a decline of 15% from the baseline). This means patients demonstrated greater memory declines of the CVLT Retreival T scores.

Grove, S. Statistics for Health Care Research: A Practical Workbook. W.B. Saunders Company, 022007. VitalBook file.